contiki/platform/sky/dev/xmem.c
2006-08-10 16:42:11 +00:00

255 lines
5.3 KiB
C

/*
* Copyright (c) 2006, Swedish Institute of Computer Science
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)$Id: xmem.c,v 1.2 2006/08/10 16:42:11 bg- Exp $
*/
/*
* Device driver for the ST M25P80 40MHz 1Mbyte external memory.
*
* Data is written bit inverted (~-operator) to flash so that
* unwritten data will read as zeros (UNIX style).
*/
#include <stdio.h>
#include <string.h>
#include <io.h>
#include <signal.h>
#include "contiki.h"
#include "dev/spi.h"
#include "dev/xmem.h"
#if 0
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...) do {} while (0)
#endif
#define SPI_FLASH_INS_WREN 0x06
#define SPI_FLASH_INS_WRDI 0x04
#define SPI_FLASH_INS_RDSR 0x05
#define SPI_FLASH_INS_WRSR 0x01
#define SPI_FLASH_INS_READ 0x03
#define SPI_FLASH_INS_FAST_READ 0x0b
#define SPI_FLASH_INS_PP 0x02
#define SPI_FLASH_INS_SE 0xd8
#define SPI_FLASH_INS_BE 0xc7
#define SPI_FLASH_INS_DP 0xb9
#define SPI_FLASH_INS_RES 0xab
static void
spi_tx(unsigned byte)
{
FASTSPI_TX(byte);
}
static void
write_enable(void)
{
int s;
s = splhigh();
SPI_FLASH_ENABLE();
spi_tx(SPI_FLASH_INS_WREN);
SPI_FLASH_DISABLE();
splx(s);
}
static unsigned
read_status_register(void)
{
unsigned char u;
int s;
s = splhigh();
SPI_FLASH_ENABLE();
spi_tx(SPI_FLASH_INS_RDSR);
FASTSPI_CLEAR_RX();
FASTSPI_RX(u);
SPI_FLASH_DISABLE();
splx(s);
return u;
}
/*
* Wait for a write/erase operation to finish.
*/
static unsigned
wait_ready(void)
{
unsigned u;
do {
u = read_status_register();
} while(u & 0x01); /* WIP=1, write in progress */
return u;
}
/*
* Erase 64k bytes of data. It takes about 1s before WIP goes low!
*/
static void
erase_sector(off_t offset)
{
int s;
wait_ready();
write_enable();
s = splhigh();
SPI_FLASH_ENABLE();
spi_tx(SPI_FLASH_INS_SE);
spi_tx(offset >> 16); /* MSB */
spi_tx(offset >> 8);
spi_tx(offset >> 0); /* LSB */
SPI_FLASH_DISABLE();
splx(s);
}
/*
* Initialize external flash *and* SPI bus!
*/
void
xmem_init(void)
{
spi_init();
P4DIR |= BV(FLASH_CS) | BV(FLASH_HOLD) | BV(FLASH_PWR);
P4OUT |= BV(FLASH_PWR); /* P4.3 Output, turn on power! */
SPI_FLASH_DISABLE(); /* Unselect flash. */
SPI_FLASH_UNHOLD();
}
int
xmem_pread(void *_p, int size, off_t offset)
{
unsigned char *p = _p;
const unsigned char *end = p + size;
int s;
wait_ready();
s = splhigh();
SPI_FLASH_ENABLE();
spi_tx(SPI_FLASH_INS_READ);
spi_tx(offset >> 16); /* MSB */
spi_tx(offset >> 8);
spi_tx(offset >> 0); /* LSB */
FASTSPI_CLEAR_RX();
for(; p < end; p++) {
unsigned char u;
FASTSPI_RX(u);
*p = ~u;
}
SPI_FLASH_DISABLE();
splx(s);
return size;
}
static const char *
program_page(off_t offset, const unsigned char *p, int nbytes)
{
const unsigned char *end = p + nbytes;
int s;
wait_ready();
write_enable();
s = splhigh();
SPI_FLASH_ENABLE();
spi_tx(SPI_FLASH_INS_PP);
spi_tx(offset >> 16); /* MSB */
spi_tx(offset >> 8);
spi_tx(offset >> 0); /* LSB */
for(; p < end; p++) {
spi_tx(~*p);
}
SPI_FLASH_DISABLE();
splx(s);
return p;
}
int
xmem_pwrite(const void *_buf, int size, off_t addr)
{
const unsigned char *p = _buf;
const off_t end = addr + size;
off_t i, next_page;
for(i = addr; i < end;) {
next_page = (i | 0xff) + 1;
if(next_page > end)
next_page = end;
p = program_page(i, p, next_page - i);
i = next_page;
}
return size;
}
int
xmem_erase(long size, off_t addr)
{
off_t end = addr + size;
if(size % XMEM_ERASE_UNIT_SIZE != 0) {
PRINTF("xmem_erase: bad size\n");
return -1;
}
if(addr % XMEM_ERASE_UNIT_SIZE != 0) {
PRINTF("xmem_erase: bad offset\n");
return -1;
}
for (; addr < end; addr += XMEM_ERASE_UNIT_SIZE)
erase_sector(addr);
return size;
}